DR-DOS 3.x

DR-DOS was initially introduced as an OEM-only product designed to address shortcomings of MS-DOS. Although it was based on Concurrent DOS 6.0, all multi-user and multitasking ability was stripped out.

The first DR-DOS release was numbered "3.31" to show it was on par with the latest shipping MS-DOS, Compaq DOS 3.31. DR-DOS also included large partition (larger than 32MB) support.

DR DOS offered some extended command line tools with command line help, verbose error messages, sophisticated command line history and editing as well as support for file and directory passwords built right into the kernel. It was also cheaper to license than MS-DO